Method for operating shaft-kilns.



H.L.DOHERTY. METHOD FOR OPERATING SHAFT KILNS. APPLICATION 3mm NOV. 6.1909.

1,034,347. Patented Jul 30, 1912.

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HENRY L. DOI-IERTY,.OF NEW YORK, N. Y.

METHOD FOR OPERATING SHAFT-KILNS.

Specification of Letters Patent.

Patented July so, 1912.

Griginal application filed October 29, 1809, Serial No. 525,390. Dividedand this application filed November 6,1909. Serial No. 526,588.

To all whom it may concern:

Be it known that I, HENRY L. Donnn'rr, a citizen of the United States,and a resident of New York city, in the county of New York and State ofNew York, have invented certain new and useful Improvements in Methodsfor Operating Shaft-Kilns, of; which the following is a specification.

My invention relates to a method of operating shaft-kilns for theburning of ce g ramic ware, and specifically to the application of suchmethod to the continuous shaftkiln for the burning of ceramic waredescribed and claimed in my co-pending application Ser. No. 525890,filed Oct. 29th 1909, of which this application is a division.

The specific object of my invention is to supply a method for charging,supporting in the kiln, and withdrawing from the kiln, the materialwhich is to be treated in the kiln.

This invention is not limited in its application to the burning of thespecific kiln of material mentioned but may be applied to the burning ofvarious other materials.

Briefly, my invention consists in a method of supporting the charge in acontinuous kiln, in which the charge for the kiln is added at the topand the burned material withdrawn at the bottom, which comprises.building into the charge as the same is introduced at the top of thekiln courses of special hollow tiles at such intervals in the chargethat the same is divided into sections, the quantity of material in eachsection corresponding to the quantity of ma terial which it is desiredto withdraw from the kiln at each draw the said hollow tiles being laidend to end in parallel rows, whereby there is formed a plurality ofgroups of continuous transverse passages through the charge, thepassages in each group being at the same level in the charge, supportingthe charge at the moment of drawing by a vertically movable platform inthe lower part of the shaft of the kiln, lowering said platform for adistance cor-- v responding to the interval between said specialcourses, whereby a group of said transverse passages is brought oppositecooperating groups of ports in opposite (and accessible) walls of thekiln, inserting bars? through said ports and the group of trans- .i

verse passages opposite said ports, and continuing the downward movementof the 4 platform, whereby the section of the charge below the said barsis detached from the superincumbent column of the charge and mayberemoved from the said platform.

In the accompanying drawing, I have shown part sections through a brickkiln of the type described in my application above referred to, showinga charge of bricks supported according to the method which I hereinclaim.

Figure l is a horizontal part section through a battery of the kilnstaken on a plane through the lines A B and A B of Figs. 2 and 3,respectively, 2'. 6., through one of the special tile courses. Fig. 2 isa vertical part sect-ion through one of the kilnson the lines C D ofFig. 1 and C D of Fig. 3. Fig. 3 is a similar section on the lines E FofFig. 1 and E F of Fig.2.

1, 1, 1", etc., indicate the individual kilns of a battery, the detailedconstruction of which is not pertinent to the present application sincemy invention may be used in connection with any type of-shaft kiln inwhich the shaft does not converge toward the bottom.

2, refers to the special hollow tiles built into the charge in the kiln.A

' 2, 2", etc., refer to the several courses of special tiles 3,3, 3,etc., and 3, 3, 3, etc., refer to the two opposite groups of ports inkiln 1, through which the false bars 4, 4;, 4, etc., are inserted.

5 and 5 refer to-the arches at the bottom of kiln 1, which provideaccess to the vertically movable platform 6, for the purpose of removingthe detached portion of the burned and cooled charge during the drawingof the kiln.

7, 7, 7", etc., refer to the groups of transverse passages formed by thesimilarly accented groups of special tiles, 2, 2, 2', etc.

8 and 8 are the covers of the sets of ports in the two opposite walls 9and 9 of kiln 1.

In the operation of the kilns the air for the burning of the charge isadmitted at the bottom of the kiln and passes up through the lower partof the shaft of the kiln, cooling the material therein. Above thecooling zone of the kiln combustible gas is introduced which mingleswith the air and burns in contact with the material occupying thatportion of the kiln. When the section of the charge in contact with theflame has been burned and the section in the lower portion of the columnhas been cooled, it is necessary to remove the cooled material at thebottom of the shaft, and cause the column of the charge to sink downthrough the shaft in order to bring a fresh portion of the charge intothe burning zone. With materials such as limestone, this is accomplishedby simply drawing material from the bottom of the charge and permittingthe material in the superincumbent portion of the charge to settle asthe support of the bottom is removed. \Vith such materials as brick,tiles, pottery ware, etc., this method of operating is entirelyimpracticable. The charge does not settle uniformly as a whole, but bythe more or less independent movement of its fragments. There is amutual grinding action between the fragmentsthat reduces more or less ofthe material to powder and causes, even with material of great strength,the formation of a large proportion of fines. If such a method wereapplied to fragile ware such as brick and tiles, etc., the loss due tobreakage would be prohibitive. By my method of operating,however, I amable to draw the finished material from the bottom of the kiln and causethe necessary downward progression of the charge as a unit withoutsubjecting the individual pieces in the charge to any but the constantand uniform compression stress due to the weight of the superincumbentcharge. As is well known to those skilled in the art, ordinary potteryvessels will bear without fracture a comparatively high compressionstress, properly applied, while they will be fractured by a very lightimpact or bending stress.

In carrying out my invention, I build the charge into my kiln as aunitary column structure, dependent simply upon its basal support forstability and entirely independent of the kiln walls. By simply causingthe downward movement of the basal support I am able, therefore, tocause the downward movement of the charge as a unitary structure andwithout any relative movement among the individual pieces making up thecharge. In order to provide for a fresh downward movement of the chargewhen another section of the same is ready for withdrawal from the kilnit is necessary to remove the lower finished section of the chargeresting upon the basal support without interfering with the stability orstructural arrangement of the upper portion of the charge column. Thisresult I secure by temporarily support-- ing the portion of the chargeabove that which it is desired to remove by false bars while the basalsupport is further lowered, thereby detaching from the main column ofthe charge that portion which it is desired to remove, when such portionmay be easily removed from the supporting platform piece by piecewithout any danger of injury.

According to my invention I provide a vertically-movable platform, 6,closing the lower part of the kiln shaft, above the crowns of the arches5, 5, the said platform being supported upon the plunger of a hydraulicram or in any other suitable manner, which will permit of the controlledvertical movement of the platform, at will. Upon this platform 6, I laya course of hollow tiles, 2, the tiles being laid in parallel rows endto end so that the hollow interiors of the tiles in each row form acontinuous passage across the shaft. The tiles in each row may be laidwith their ends in contact or they may be spaced from one-half to oneinch apart. Between the rows I leave an interval of from 2 to 8 inches,more or less, according to circumstances. Built into opposite walls ofthe kiln 9, 9 are sets of ports 3 and 3, respectively, the said portsbeing so located that they will register with the transverse passagesformed by the tiles. These ports, when the platform 6 is in its highestposition are designed to permit of the entry of air to support thecombustion in the kiln and are provided with adjustable covers 8, 8 sothat the quantity of air entering the ports may be regulated at will.Upon this first tile course, I build a section of already burned brickor other ware, of the kind that the kiln is designed to work upon.Upon.this I lay another course of the special hollow tile similar to theone laid in contact with the platform 6, build another section of thecharge thereon as before and so continue until the shaft has been filledwith a column of material which is supported entirely by the platform 6.The height of the different sections of the charge should be the same,and should be that of the height of the section of the charge which itis designed to withdraw at one operation of draw. Care must be takenthat in laying the special courses of hollow tiles the correspondingrows of each coinse must be located in the same vertical position, sothat the transverse passages which they form will register with thecorresponding couples of ports when that course has sunk to the level ofthe ports. In building in the actual material of the charge proper whileit is not necessary to observe any special arrangement the structureshould be left sufficiently open to afford free passage to the gaseouscurrent passing through the kiln. In the case of the burning of brickany pattern of checker-work construction may be used in the charge.

IVhen the kiln-shaft has been filled with a charge of already burnedmaterial a section of green or unburned material is built onto thecharge in the manner already described. The fires are started, theproducer or other gas being admitted at a level a considerable distanceabove the lower part or cooler of the kiln. When the portion of theinitial charge occupying the firing zone of the kiln has been heated upto the proper burning temperature the drawing of the kiln is begun. Theplatform 6 is slowly lowered until thepassages 7 formed by the secondspecial course register with the sets of ports 3, 3. Thedownward motionof the platform is now stopped and the bars 4 inserted through one setof ports, through the passages 7 and into the opposite set of ports. Theplatform 6, is again gradually dropped, the bars 4iengaging the tops ofthe passages 7 and bringing the whole column of the charge above thebars to rest, while the section of the charge below the bars follows thedownward movement of the platform. This material on the platform 6 isremoved and the platform again raised above the arches 5, 5 ready foranother draw and another section of green ware is built onto the top ofthe column. When the section just brought into the firing zone has beenheated up to the proper point, the kiln is in condition for another drawThe platform 6 is slightly raised until it engages the bottom of thecourse 2 and lifts the entire column of the charge off the bars 4. Theseare withdrawn through either the ports 3 or 3 and the operationdescribed above repeated.

It is obvious, that the size of the hollow tiles used will dependprimarily upon the size of the bars that are 'to be used and this inturn, will depend upon the weight of the column of charge that is to becarried in the kiln.

Having described my invention, what I claim is 1. The method ofoperating continuous shaft-kilns for the burning of ceramic ware whichcomprises interposing bet-ween charges a course of hollow tiles, thesaid tiles being arranged so as to form a plurality of transversepassages through the charge column, the said passages-being spaced toregister with cooperating groups of ports located in opposite walls ofsaid kiln near the bottom thereof when they have reached 3. The methodof operating continuous shaft-kilns for the burning of ceramic warewhich comprises interposing between the separate charges of saidshaft-kiln a course of blocks of refractory material each of said blockshaving a rectangular section and an interior longitudinal openingtherethrough,

the blocks composing said course being laid end to end in substantiallyparallel rows, the longitudinal openings of the blocks in each rowforming an open transverse passage through the charge in said kiln, thesaid rows of blocks being laid with an interval between each twoadjacent rowsv and so spaced that the plurality of transverse passagesformed by the said blocks will register with cooperating groups of portsin opposite walls of said kiln near the bottom thereof, when the saidtransverse passages have been carried down to the level of said ports bythe subsidence of the charge column.

4:. The method of operating continuous shaft-kilns for the burning ofceramic ware which comprises building onto the top of the charge-columnoccupying the shaft of said kiln, alternately, a charge of the mate rialto be burned and a course of blocks of refractory material each of saidblocks having a rectangular section and an interior openingtherethrough, the blocks comprising said course being laid end to end insub stantially parallel rows the interior openings of the blocks in eachrow forming an open transverse passage across the chargecolumn, the saidrows of blocks being laid with an interval between each two adjacentrows and so spaced that the axis of each passage will be in the samevertical plane with the axis of one of a plurality of cooperatingcouples of ports located in opposite walls of said kiln near the bottomthereof, whereby said charge-column is divided into sections separatedby the said courses of blocks, each course of blocks being adapted tosupport the weight of the superincumbent portion of the charge column.

5. The method of operating continuous shaft-kilns for the burning ofceramic ware which comprises building onto the top of the charge-columnoccupying the shaft of said kiln, alternately, a charge of thematerial-to be burned and a course of blocks of refractory material eachof said blocks hav- 'ing its upper and lower surfaces substan tiallyparallel and an interior opening, the

blocks composing said course being laid end to end with intervalsbetween the blocks in substantially parallel rows, the said interioropenings of the blocks in each row forming an open transverse passageacross the chargecolumn, the said rows of blocks being so spaced thatthe axis of each passage formed by the interior openings of the blockswill be substantially in the same vertical plane with the axis of one ofa plurality of cooperating couples of ports located in opposite walls ofsaid kiln near the bottom thereof, inserting bars through said ports andeach group of said transverse passages when the passages of said groupregister with said port, removing the portion of the charge column belowthe course supported by said bars, lifting the weight of the chargecolumn off of said bars, withdrawing said bars, lowering said chargecolumn until the transverse passages of the next course of blocksregister with said ports and repeating the said operations insubstantially the manner described.

6. The method of operating continuous shaft-kilns for the burning ofceramic ware which comprises building onto the top of the charge-columnoccupying the shaft of said kiln, alternately, a charge of the materialto be burned and a course of blocks of refractory material each of saidblocks having its upper and lower surfaces substantially parallel and aninterior opening therethrough, the blocks composing said course beinglaid end to end with intervals between the blocks in substantiallyparallel rows, the said interior openings of the blocks in each rowforming an open transverse passage across the charge-column, the saidrows of blocks being so spaced that the axis of each passage formed bythe interior openings of the blocks will lie, substantially, in the samevertical plane with the axis of one of a plurality of cooperatingcouples of ports lo cated in opposite walls of said kiln near the bottomthereof, whereby the charge-column is divided into sections separated bythe said courses of blocks each course of blocks being adapted tosupport the weight of the super incumbent portion of the charge column,communicating a downward movement to the charge, inserting bars throughsaid ports and the corresponding transverse passages in the first ofsaid courses of blocks to register with said ports, whereby the downwardmovement of said course and the portion of the charge superincumbent tosaid course is interrupted, while the downward movement of the portionof the charge below said course continues and such portion is detachedfrom the rest of the charge column, removing said portion of the chargefrom its support, raising said support to engage the course of blockssupported by said bars,

and after sufiicient time has elapsed to properly burn the fresh portionof the charge carried into the firing Zone of the kiln by the formerdownward movement of the charge, raising said support to lift the weightof the charge column from said bars, withdrawing said bars, andrepeating the above operation, substantially in the manner described.

7. The method of operating shaft kilns for the continuous burning ofceramic materials which comprises interposing between the charges tosaid kiln courses of special hollow tiles, the said tiles being arrangedto form a plurality of substantially parallel transverse passagesthrough said charge column, communicating an intermittent downwardmovement to said charge column, whereby the cer mic material and thespecial tiles are caused to traverse the burning zone of said kiln,withdrawing the said burned ceramic material and the special tiles fromsaid kiln when they have reached the bot tom thereof, separating thesaid special tiles from the burned ceramic material, returning the saidspecial tiles to the top of said kiln and rebuilding them into thecharge column at the top thereof with a fresh charge of the ceramicmaterials to be burned.

8. The method of operating continuous shaft kilns for burning ceramicmaterials which comprises interposing between the several charges of theunburned ceramic ware courses of burned perforated tiles, the said tilesbeing laid end to end with their perforations substantially horizontalwhereby a plurality of substantially parallel transverse passages areformed at intervals in the charge column in said kiln, said passagesbeing so located as to register with a corresponding number of openingsnear the lower part of the shaft of said kiln. whereby bearing bars maybe inserted through said. openings and said transverse passages tosupport the weight of the charge column superincumbent to each of saidspecial courses of hollow tiles when the transverse passages of saidcourse register with said openings in the kiln walls, removing from theshaft of said kiln that portion of the charge column below the course ofspecial tiles which is at the time resting upon said bearing bars,separating from the portion of the charge column, so removed, the saidspecial perforated tiles therein contained, returning the same to thetop of said kiln and interposing them between fresh charges of theceramic materials to said kiln, in the manner described.

9. In the operation of continuous shaft kilns for burning ceramicmaterials, the method of maintaining non-distortable transverse passagesin the charge column in said kiln during the passage of the said chargecolumn through said kiln which comprises building onto the top of thechargecolumn occupying the shaft of said kiln, alternately, a charge ofthe material to be burned and a course comprising special blocks ofburned refractory material, each of said blocks having its upper andlower surfaces substantially parallel and an interior openingtherethrough, the blocks comprising said courses being laid end to endwith intervals between the blocks in substantially parallel rows, theinterior openings of the blocks in each row forming an opennon-distortable passage across the charge-column, the said rows ofblocks being so spaced that the axis of each passage formed by theinterior openings of the blocks will be in substantially the samevertical plane with the axis of one of a plurality of cooperatingcouples of ports located in opposite walls of said kiln near the bottomthereof, inserting bars through said ports and each group of saidtransverse passages when the passages of said group register with saidport, removing the portion of the charge column below the course ofspecial blocks supported by said bars, separating the special blocks, inthe said portion of the charge-column removed, from the burned ceramicmaterial, returning the said special blocks to the top of said kiln andrebuilding them into a fresh charge-of raw ceramic materialsubstantially in the manner described.

10. In the operation of continuous shaft kilns, the method whichcomprises maintaining in circulation through said kiln a plurality ofhollow previously burned tiles, the said hollow tiles being charged atthe top of said kiln in special courses alternately with charges of theraw material to be burned, separated from the burned material withdrawnat the bottom of said kiln, returned to the top of said kiln and againrecharged at the top thereof substantially in the manner described.

Signed at New York city in the county HENRY L. DOHERTY.

Witnesses:

TI-IOS. I. CARTER, W. J. QUENTIN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. O.

